For the thousands of flight students who passed through the training command during World War II and Korea, learning the nuances of instrument flying began on the ground in a Link Trainer, a device designed by Edwin Link, a former organ manufacturer turned aviator. The Trainer could simulate various flight conditions, including wind drift, turbulence and radio static, and could put the aircraft in various flight orientations. Air nozzles even produced the sound effect of the slipstream. Better still, the cost to operate the device was relatively low. Each instrument flight in a training aircraft cost the military $10 per hour, while the Link Trainer only cost 4¢ per hour. Further, no cadet could lose his life if he committed an error in the simulator.